Cannot delete file on USB HDD connected to router

Windows 10, Ver 20H2

I have a HDD used for backup purposes connected to my Asus RT-N66U router. There are a few files/folders which I want to delete but I "...need permission to perform this action." Apparently, I "...require permission from RT-N66U-5088\admin to make changes ..." I believe I need to change ownership for the file, but for the life of me I don't know to do it. What follows is the security tab of the file properties.


As you can see, "Everyone" has full rights, but I guess that it doesn't include me. Perhaps it means everyone in the router! Anyway, an explanation of what's happening is appreciated and, of course, what to do is paramount.

While you're at it, I would like an explanation as to how to reorganize the folders within the router-connected HDD, i.e., move them into a newly created folder which I already added from the router's control UI (via 192.168.1.1 web page).

Thanks in advance.
Leo

Have you looked at this tutorial? Change Owner of File, Folder, Drive, or Registry Key in Windows 10

Also, this: Enable or Disable Inherited Permissions for Objects in Windows

Have you tried connecting the hdd to your computer and seeing if that allows you to carry out the tasks?

Yes, connecting the HDD directly to the PC does work, and thanks for that suggestion, but I would still like to be able to do it remotely, like from my laptop.
As to taking ownership as another member suggested, the issue is I don't know how to construct the path to the PC wanting to take ownership. For example, the path to the file is \\RT-N66U-5088\Dad_Desktop\FILENAME, but what is my path?